Water outlet box provided with a thermostat and manufacturing process

ABSTRACT

A water out-let box comprising a regulating thermostat principally made up of a valve to block an opening of a passage emerging in the box, the valve being stressed against its seat, formed by the peripheral edge of the above-mentioned opening, by an elastic loading means and moved away from the seat by a pressure means that reacts to heat, the means with opposed actions resting, directly or indirectly, on a stress-absorbing clamp which also ensures that the thermostat is mounted and positioned in cooperation with an opposed bearing. Box is produced in a thermoplastic material and comprises, on the internal face of its constitutive wall ( 1 ′), at least two internal protrusions ( 10, 10 ′) providing permanent support surfaces ( 10 ″) for the clamp ( 9 ) of the thermostat ( 2 ), before and after installation of the box ( 1 ).

TECHNICAL FIELD

The present invention relates to the field of means for regulating fluidcirculation, particularly in relation to equipment for automobilevehicles. Its object is a water outlet box provided with a thermostat,and a manufacturing process for such a box with an integral thermostat.

BACKGROUND ART

Outlet boxes for thermal engines are generally installed in the regionof the cylinder heads of said engines, or mounted directly thereon, andprovide controlled cooling of said cylinder heads, by regulating theflow of cooling liquid in contact therewith.

These thermostats comprise essentially a valve mounted in mobiletranslation, to block or release an opening in said box, guided over aspindle and subject to the opposed stresses of an elastic means, such asa compression spring, forcing said valve in the closed position and aheat activated means, such as a wax cartridge, forcing said valve in theopen position counter to the above-mentioned elastic stress.

Various embodiments of such a water outlet box are already known, butthey all have limitations in terms of manufacturing costs and/orcomplexity of manufacturing and/or installation.

Thus, according to a first known embodiment, the thermostat is enclosedin a metal shell providing the valve seat and an opposed wall portion toabsorb stresses, having an external radial edge intended to be squeezedbetween the two parts constituting said box assembled by screwing, witha peripheral sealing strip placed between them. This results in acomplex, costly structure that requires special additionalimpermeability.

According to a second known embodiment, the box is made of athermosetting material or of aluminium and comprises an opening forminga valve seat and opposed lips to support the stress-absorbing clamp ofthe thermostat.

Said box may be made in a single piece being attached directly to thecylinder head or in two parts assembled by mechanical means ofconnection, with a sealing strip placed between them.

A third existing solution proposes producing the body of the box in aplastics material, which box comprises an opening forming a valve seatand radial tongues to engage the stress-absorbing clamp and temporarilyretain the thermostat, between its mounting in the box and fixing saidbox on the cylinder head. After fixing, the clamp rests directly on saidcylinder head, which absorbs all the axial stresses applied in theopposite direction to the valve. Nevertheless, in this last solution, itis also necessary to make a special assembly with a sealing stripinterposed.

Consequently, the problem posed consists of overcoming the limitationsof the existing solutions set out above and providing a water outlet boxincorporating a thermostat in the form of a pre-fabricated module,preferably closed.

DISCLOSURE OF INVENTION

For this purpose, the object of the present invention is a water outletbox, in particular for the cylinder head of an internal combustionengine, comprising a regulating thermostat substantially consisting of avalve to block an opening of a passage emerging in said box, said valvebeing carried and centred by a portion of frontal spindle engaged in abearing, which is integral with the box, stressed against its seat,formed by the peripheral edge of the above-mentioned opening, by anelastic loading means and moved away from said seat by a pressure meanswhich reacts to heat, said means with opposed actions resting, directlyor indirectly, on a stress-absorbing clamp which also ensures that saidthermostat is mounted and positioned in cooperation with said bearing,characterised in that said box is produced in a thermoplastic materialand comprises, on the internal face of its constitutive wall, at leasttwo internal protrusions providing permanent support surfaces for theclamp of said thermostat, before and after installation of said box.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be better understood, using the description below,which relates to a preferred embodiment, given as a non-restrictiveexample, and explained with reference to the accompanying diagrammaticdrawings, in which:

FIG. 1 is a view in cross-section along a plane passing through thelongitudinal axis of the thermostat of a water box according to theinvention, and,

FIG. 2 is a perspective view in the direction of the opening to beblocked, of the internal volume of the first part of the box accordingto the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

As shown by the figures of the accompanying drawings, the water outletbox 1 comprises a regulating thermostat 2 which is substantially formedby a valve 3 intended to block an opening 4 of a passage 4′ emerginginto said box 1, said valve 3 being carried and centred by a portion offrontal spindle 5 engaged in a bearing 6 integral with the box 1.

The valve is stressed against its seat 4″, formed by the above-mentionedperipheral edge of the opening 4, by an elastic loading means 7 andmoved away from said is seat 4″ by pressure means 8 that reacts to heat,said means 7 and 8 with opposed actions resting, directly or indirectly,on a stress-absorbing clamp 9 that also ensures the assembly andpositioning of said thermostat 2 in cooperation with said bearing 6.

In accordance with the invention, said box 1 is made of a thermoplasticmaterial and comprises, on the internal face of its constitutive wall1′, at least two internal protrusions 10, 10′ providing permanentsupport surfaces 10″ for the clamp 9 of said thermostat 2, before andafter installation of said box 1.

According to a simple and advantageous embodiment of the invention, theclamp 9 has a structure in the form of a small plate and comprises twoopposed lateral legs 9′ and the protrusions 10 and 10′ consist of twoopposed internal radial projections of the wall 1′ of the water box 1formed in one piece with the wall.

Preferably, the two opposed radial projections 10 and 10′ are formed bylocalised thickenings of the wall 1′ of the box 1 having, in thedirection of the bearing 6 receiving the portion of spindle 5 integralwith the valve 3, support surfaces 10″ situated in a plane perpendicularto the longitudinal axis X of the thermostat 2, the portions 11 of theinternal face of the wall 1′ adjoining said support surfaces 10″ ofprojections 10, 10′ constituting the centring surfaces, coaxial to theinternal surface of said bearing 6 and intended to cooperate with theends of the legs 9′ of the clamp 9 to retain the clamp laterally.

Said projections 10, 10′ comprise connecting interfaces with thelarge-area wall 1′, providing good resistance to shearing through gooddistribution of stresses.

As shown in FIG. 1 and 2 of the accompanying drawings, the box 1 has,advantageously, a cylindrical structure with a circular section, ofwhich the longitudinal axis merges with the axis X of the thermostat 2in the mounted state, the internal protrusions 10, 10′ extending, viewedin a plane perpendicular to the axis X of the box 1, along tworestricted arcs of a circle and forming two diametrically opposedannular portions.

In accordance with a practical variant embodiment producing a closedwater outlet box module 1, the box is formed of two complementary parts12 and 12′ assembled together by vibration welding at a joint face Pperpendicular to the axis X of the thermostat 2 in the mounted state andsituated beyond the internal protrusions 10, 10′.

One of the constitutive parts 12, 12′ may, for example, be integral withor comprise a fixing plate 13 of which the shape and configuration aresuited to the installation site of said water outlet box 1.

To secure the assembly of the thermostat 2 in the box 1, provision maybe made for support surfaces 10″ comprising sites, recessed orprotruding, for indexing or engaging the lateral legs 9′ of thestress-absorbing clamp 9 of the thermostat 2, intended, if necessary, toengage in a complementary manner with the specific formation of saidlegs 9′.

If necessary, the legs 9′ may therefore have folded edges providinglateral wedging of said legs on said projections 10, 10′.

According to an additional characteristic of the invention, the twoconstitutive parts 12, 12′ are produced advantageously in PA66containing glass fibres.

The object of the invention is also a manufacturing process for thewater outlet box 1 as described above.

In accordance with the invention, this process consists essentially ofproviding a first open part of box 12, of substantially cylindricalshape and comprising an opening 4 forming a valve seat and at least twoopposed internal protrusions 10, 10′ provided with support surfaces 10″directed towards said opening 4, then in providing and introducing athermostat 2 in said first box part 12 in such a way that the portion offrontal spindle 5 adjacent to the valve 3 is engaged in the bearing 6,in then compressing the elastic means 7 and applying the valve 3 againstits seat 4″ by pushing the stress-absorbing clamp 9 in the direction ofthe portion of frontal spindle 5 beyond the plane comprising the supportsurfaces 10″ of the protrusions 10, 10′, in turning said clamp 9 aboutthe longitudinal axis X of the thermostat 2, while maintaining thepressure, until the lateral legs 9′ of said clamp 9 are situatedopposite said support surfaces 10″, in then releasing said pressure insuch a way that said legs 9′ come to rest against said surfaces 10″ and,possibly, engaging said legs 9′ with said support surfaces 10″ and,finally, in providing a second part 12′ of the water outlet box, whichis complementary to the first part 12, and positively connecting it tothe first part by vibration welding.

Of course, the invention is not restricted to the embodiment describedand illustrated in the accompanying drawings. Modifications arepossible, in particular from the point of view of the formation of thevarious elements or by substitution of equivalent techniques, withouthowever departing from the scope of protection of the invention.

1. Water outlet box, in particular for the cylinder head of an internalcombustion engine, comprising a regulating thermostat substantiallyconsisting of a valve to block an opening of a passage emerging in saidbox, said valve being carried and centred by a portion of frontalspindle engaged in a bearing, which is integral with the box, stressedagainst its seat, formed by the peripheral edge of the above-mentionedopening, by an elastic loading means and moved away from said seat by apressure means which reacts to heat, said means with opposed actionsresting, directly or indirectly, on a stress-absorbing clamp which alsoensures that said thermostat is mounted and positioned in cooperationwith said bearing, characterised in that said box (1) is produced in athermoplastic material and comprises, on the internal face of itsconstitutive wall (1′), at least two internal protrusions (10, 10′)providing permanent support surfaces (10″) for the clamp (9) of saidthermostat (2), before and after installation of said box (1).
 2. Boxaccording to claim 1, characterised in that the clamp (9) has astructure in the form of a small plate and comprises two opposed laterallegs (9′) and that the protrusions (10 and 10′) consist of two opposedinternal radial projections of the wall (1′) of the water box (1) formedin one piece with the wall.
 3. Box according to claim 2, characterisedin that the two opposed radial projections (10 and 10′) are formed bylocalised thickenings of the wall (1′) of the box (1) having, in thedirection of the bearing (6) receiving the portion of spindle (5)integral with the valve (3), support surfaces (10″) situated in a planewhich is perpendicular to the longitudinal axis (X) of the thermostat(2), the portions (11) of the internal face of the wall (1′) adjoiningsaid support surfaces (10″) of the projections (10, 10′) constitutingthe centring surfaces, coaxial to the internal surface of said bearing(6) and intended to cooperate with the ends of the legs (9′) of theclamp (9) to retain the clamp laterally.
 4. Box according to claim 1,characterised in that it has a cylindrical structure with a circularsection, of which the longitudinal axis merges with the axis (X) of thethermostat (2) in the mounted state, the internal protrusions (10, 10′)extending, viewed in a plane perpendicular to the axis (X) of the box(1), along two restricted arcs of a circle and forming two diametricallyopposed annular portions.
 5. Box according to claim 1, characterised inthat it is made of PA66 containing glass fibres.
 6. Box according toclaim 1, characterised in that it is formed of two complementary parts(12 and 12′) assembled together by vibration welding at a joint face (P)perpendicular to the axis (X) of the thermostat (2) in the mounted stateand situated beyond the internal protrusions (10, 10′).
 7. Box accordingto claim 1, characterised in that the support surfaces (10″) comprisesites, recessed or protruding, for indexing or engaging the lateral legs(9′) of the stress-absorbing clamp (9) of the thermostat (2), intended,if necessary, to engage in a complementary manner with the specificformation of the said legs (9′).